Review of UNCERTAINTY, Biography of Werner Heisenberg, Part II

Part 2 of 2

Besides describing his scientific achievement, uncertainty can also describe Heisenberg’s actions, as Cassidy also points out in the preface. The uncertainty of Heisenberg’s life lies in his refusal to take a public stand on political issues and the questionable decisions and compromises he made. Cassidy shows the numerous times in Werner’s life where he explicitly rejected politics as an activity not meant for the objective scientist; his refusal to get involved persisted in the face of the inhumanity perpetrated by the regime against the Jews. However, despite this refusal to participate in politics, Heisenberg actually possessed shrewd political skills which he used to protect himself and his physics. Hidden in Heisenberg’s public equivocation was a complex mixture of love of country and love of physics which Cassidy sets out to unpack.

One of the uncertainties Cassidy tries to understand was mentioned earlier: How come Heisenberg did not leave Germany, even though he was beset with overt hostility? At first sight, this stubborn refusal to leave the country may indicate sympathy towards the Reich - but Cassidy shows that this decision was not due to loyalty to Hitler and the Nazis. Heisenberg saw himself as the protector of German science, and by extension, German culture. While he was in favor of the general ideals of German superiority and prosperity, in private he expressed concern about the actions of the Reich and hoped that the Regime would either change its questionable methods or would be replaced. He also thought that if he left to join his colleagues who had already fled, he would be abandoning German physics to a catastrophe from which it would never recover. Heisenberg refused to leave Germany because of his patriotism and his deep love for German culture, crackpot regime be damned. While Cassidy understands this motive ideologically, he faults Heisenberg’s refusal to make a stand against the regime simply in support of the basic human rights of the Jewish scientists who had been wronged. Cassidy concludes that Heisenberg went wrong in prioritizing a vague sense of guardianship of German science over fundamental human concerns; indeed, Heisenberg’s first concern during the American invasion of his hometown was not for his family, but for his laboratory and lab assistants. The key is that though Heisenberg was definitely weak in the support of the marginalized, this weakness in itself does not make him either a Nazi or evil, but a fallible human caught in a terrible situation.

Heisenberg’s actions during World War II are also marked by uncertainty. Cassidy again shows that German science was to be the prime beneficiary of Heisenberg’s actions, with secondary benefits going to the German war machine. Cassidy firmly rejects Heisenberg’s postwar claim that the German scientists did not want Hitler to have an atom bomb and thus reined in their efforts in order to put the bomb out of reach. Historical analysis shows that the scientists were in fact working as hard as they could to harness nuclear energy for the benefit of the regime; Heisenberg’s motives were more complex than they first appeared.

On one hand, there is some evidence to indicate that Heisenberg might have purposefully held back just enough information in order to discourage the regime about the prospect of a bomb. Most strikingly, Heisenberg made some computational errors that convinced the Nazi powers that a bomb would be more difficult to build than it actually turned out to be; whether these were true errors or more purposeful may never be resolved. On the other hand, however, Heisenberg’s love of country and his concern for German physics did propel him to work very hard on the bomb, as Cassidy’s evidence indicates.

In the end, Cassidy’s conclusion is that Heisenberg “walked a fine line” – he wanted to harness nuclear power not necessarily for the glory of the regime or of Germany as a whole, but supremely for the glory of German science. Again, one sees how science was center to Heisenberg’s life and his allegiance to it, for better or for worse, was stronger than any allegiance to the Reich or even allegiances to his friends and family.

Cassidy concludes that while Heisenberg was not an “evil Nazi,” he was certainly morally weak and too focused on his imagined role as vanguard of German science to take a stand against the very real human tragedy transpiring around him. Cassidy resolves some of the uncertainty surrounding Heisenberg’s life, thought not all of it, by showing that Heisenberg was a complex character reacting to complex times. I recommend this book to those interested in the history of science in Germany during the Nazi regime, those interested in the development of quantum mechanics, and those interested in the life of a great physicist.